On your W2 each entry is in a box, each of those boxes are labeled a number or a letter in the top left.
https://www.irs.gov/pub/irs-pdf/fw2.pdf
Please look at the W2 on this link, just scroll down a little, you will see it. Box 1 on this W2 is located near the top a little to the right side of the center. It says wages, tips, other compensation.
Some W2s will look a little different, but the information is still organized the same, the box may be in a different place, but it will still be labeled 1 at the top left corner of the box.